Pageant officials immediately said the lithe 5-foot-9 18-year-old was all right and had fainted.

"She's okay. She's fine," pageant representative Lark Anton told Reuters. "She got dizzy. It's very hot up here. Her dress is tight – as you could see it was beaded and heavy. She passed out."

Anton said Rivera "had plenty to eat today," when pressed for the beauty queen's condition before she fainted at the center of the stage at the Shrine Auditorium, where she had become the 55th Miss Universe before an international television audience less than an hour earlier.

Rivera attended the pageant's Coronation Ball after recovering from her collapse, according to guests including Donald Trump, co-owner of the Miss Universe Organization. "Yes, she's fine," Trump said as he left.

The Puerto Rican beauty queen was named Miss Universe 2006 over runner-up Miss Japan, Kurara Chibana, 24. Second runner-up was Miss Switzerland Lauriane Gillieron, 21. Rounding out the top five were Miss Paraguay Lourdes Arevalos, 22, and Miss United States, 20-year-old Tara Conner.

The youngest of the five finalists, Rivera appeared radiant as she waved to photographers several minutes before collapsing. Most of the press had left by the time she fainted.

Having lingered on stage, Rivera was leaning on some assistants when her face fell to her chest, her new tiara atop her head. Tottering on high, spiky heels, she appeared to lean in this fashion for about 10 seconds and, at 8:38 p.m., collapsed in the arms of pageant assistants.

She was rushed offstage while the organizer of a post-pageant press conference called for aid.

"Is there a nurse in the house? Can a nurse come to the stage?" said the announcer, who was not identified.

Within a minute, Anton said Rivera was fine and had merely fainted.

During her news conference, Rivera said she would carry out the work of the Miss Universe Organization, which is to work to help those with HIV/AIDS.

The Miss Universe contest was held at the fabled Shrine Auditorium near downtown Los Angeles. It was a homecoming of sorts. The first Miss Universe pageant was held about 25 miles away in Long Beach, California, in 1952.

Ending her year as Miss Universe was Canadian Natalie Glebova, who was born in Russia.